Three dimensional scanning of an object is valuable in many clinical applications. For example, in the fields of orthodontics and prosthodontics, three dimensional (3D) scanning of the teeth can provide valuable information for diagnosis and treatment such as dental restorative and orthodontics indications. Confocal 3D scanning is one of the imaging technologies that may provide such information. Confocal microscopy may be used to perform three dimensional scanning by illuminating and observing a single nearly diffraction limited spot, for example, by using a spatial pinhole to eliminate out-of-focus light. Confocal 3D scanning can be used to obtain images free of defocus-blur and may allow three-dimensional visualization of the object. Other surface topology scanners have been described, but are generally relatively bulky and may be less comfortable or may even be difficult to use. U.S. Pat. No. 8,878,905 describes a 3D scanner for obtaining the 3D geometry of an object using confocal pattern projection techniques. The 3D scanner disclosed therein uses a time varying pattern (or a segmented light source to equivalently create a time varying pattern). When the pattern is varied in time for a fixed focus plane then the in-focus regions on the object will display an oscillating pattern of light and darkness. However, the out-of-focus regions will display smaller or no contrast in the light oscillations.
Thus, there is a need for develop apparatuses and related methods for confocal scanning to have a more compact size, lighter weight and lower cost than the conventional confocal scanning apparatuses.